Could not instantiate class named IBNSLayoutConstraint

Question

I\'m using XCode6 beta and trying out Swift. When I put some auto layout constraints in a view controller the app crashes with the following error: Terminating app

Answer 1

I made a change to a scroll view so that it would let the picker controls embedded in it work properly using a solution I found elsewhere in Stackoverflow. My new storyboard simply added these attributes to the scroll view, which seemed fine to me.

     delaysContentTouches="NO" canCancelContentTouches="NO"

But in addition, I saw in my storyboard in another scene the following new fragment:

I have no idea where it came from. At first I ignored it because everything seemed to work find on my dev machine. But when the build was built as Release and tested, I got the crash. Removing that spurious(?) fragment fixed the crash and has not seemed to impact anything else.